• Journal of Aquaculture
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• v.5 no.1
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• pp.29-67
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• 1992

Life cycle and seed production of the freshwater prawn, Macrobrachium nipponense, were studied and the results are as follows : 1. Larval development : Embryos hatched out as zoea larvae of 2.06 mm in mean body length. The larvae passed through 9 zoea stages in $15{\~}20$ days and then metamorphosed into postlarvae measuring 5.68 mm in mean body length. Each zoea stage can be identified based on the shapes of the first and second antennae, exo- and endopodites of the first and second pereiopods, telson and maxillae. 2. Environmental requirements of zoea larvae : Zoea larvae grew healthy when fed with Artemia nauplii. Metamorphosing rate was $65{\~}72{\%}$ at $26{\~}28\%$ and $7.85{\~}8.28\%_{\circ}Cl.$. The relationship between the zoeal period (Y in days) and water temperature (X in $^{\circ}C$) is expressed as Y=46.0900-0.9673X. Zoeas showed best survival in a water temperature range of $26{\~}32^{\circ}C$ (optimum temperature $28^{\circ}C$), at which the metamorphosing rate into postlarvae was $54{\~}72\%$ The zoeas survived more successfully in chlorinity range of $4.12{\~}14.08{\%_{\circ}}Cl.$, (optimum chlorinity $7.6{\~}11.6\;{\%_{\circ}}Cl.$.), at which the metamorphosing rate was $42{\~}76{\%}$. The whole zoeal stages tended to be longer in proportion as the chlorinity deviated from the optimum range and particularly toward high chlorinity. Zoeas at all stages could not tolerate in the freshwater. 3. Environmental requirements of postlarvae and juveniles : Postlarvae showed normal growth at water temperatures between $24{\~}32^{\circ}C$ (optimun temperature $26{\~}28^{\circ}$. The survival rate up to the juvenile stage was $41{\~}63{\%}$. Water temperatures below $24^{\circ}C$ and above $32^{\circ}$ resulted in lower growth, and postlarvae scarcely grew at below $17^{\circ}C$. Cannibalism tended to occur more frequently under optimum range of temperatures. The range of chlorinity for normal growth of postlarvae and juveniles was from 0.00 (freshwater) to $11.24{\%_{\circ}}Cl.$, at which the survival rate was $32{\~}35\%$. The postlarvae grew more successfully in low chlorinities, and the best growth was found at $0.00\~2.21{\%_{\circ}}Cl.$. The postlarvae and juveniles showed better growth in freshwater but did not survive in normal sea water. 4. Feeding effect of diet on zoea Ilarvae : Zoea larvae were successfully survived and metamorposed into postlarvae when fed commercial artificial plankton, rotifers, and Artemia nauplii in the aquaria. However, the zoea larvae that were fed Artemia nauplii and reared in Chlorella mixed green water showed better results. The rate of metamorphosis was $68\~{\%}75$. The larvae fed cow live powder, egg powder, and Chlorella alone did not survive. 5. Diets of postlarvae, juveniles and adults : Artemia nauplii and/or copepods were good food for postlarvae. Juveniles and adults were successfully fed fish or shellfish flesh, annelids, corn grain, pelleted feed along with viscera of domestic animals or fruits. 6. Growth of postlarvae, juveniles and adults : Under favorable conditions, postlarvae molted every five or six days and attained to the juvenile stage within two months and they reached 1.78 cm in body length and 0.17 g in body weight. The juveniles grew to 3.52 cm in body length and 1.07 g in body weight in about four months. Their sexes became determinable based on the appearance of male's rudimental processes (a secondary sex character) on the endopodites of second pereiopods of males. The males commonly reached sexual maturity in seven months after attaining the postlarvae stage and they grew to 5.65 cm in body length and 3.41 g in body weight. Whereas the females attained sexual maturity within six to seven months, when they measured 4.93 cm in body length and 2.43 g in body weight. Nine or ten months after hatching, the males grew $6.62{\~}7.14$ cm in body length and $6.68{\~}8.36$ g in body weight, while females became $5.58{\~}6.08$ cm and $4.04{\~}5.54$ g. 7. Stocking density : The maximum stocking density in aquaria for successful survival and growth was $60{\~}100$ individuals/$\ell$ for zoeas in 30-days rearing (survival rate to postlarvae, $73{\~}80{\%}$) ; $100{\~}300$ individuals/$m^2$ for postlarvae of 0.57 cm in body length (survival rate for 120 days, $78{\~}85{\%}$) ; $40{\~}60$ individuals/$m^2$ for juveniles of 2.72 cm in body length (survival rate for 120 days, $63{\~}90{\%}$) : $20{\~}40$ individuals/$m^2$ for young prawns of 5.2 cm in body length (survival rate for 120 days, $62\~90{\%}$) ; and $10\~30$ individuals/$m^2$ for adults of 6.1 cm in body length (survival rate for 60 days, $73\~100{\%}$). The stocking density of juveniles, youngs and adults could be increased up to twice by providing shelters.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.380-381
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• 2003

석패과 종의 발생은 체내수정을 하며 산란시기는 계절에 따라 차이가 나는 것으로 알려져 있다 이들 종들은 아가미내에서 피면자 시기에 해당되는 유생인 글로키디움까지 발생 시기를 거친 후 유생이 체외로 방출되면 물고기 둥 수서생물에 부착하여 일정기간 기생생활을 거쳐 유패로 탈락하면서 독립생활을 하게 된다. 또한 석패과 유생의 발달과 분산의 형태는 곧 종의 수명과 지리적 분산의 중요한 역할을 하는 것으로 알려져 있다 (Jackson, 1974). (중략)

• Animal Systematics, Evolution and Diversity
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• v.19 no.1
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• pp.49-55
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• 2003

The first larval stage of Neocaridina denticulata sinensis (Kemp, 1918) is described and illustrated in detail. The first larvae of N. d. sinensis are compared with those of four other known congeners of Neocoridina from Asia.

• Journal of Aquaculture
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• v.19 no.4
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• pp.288-298
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• 2006

Larval distribution of bivalve from 29 stations in Deukryang Bay was examined from May to November in 1995. The abundance of total larvae increased from May ($3,736\;inds/m^3$) and reached maximum in August ($174,616\;inds/m^3$). But it decreased continuously until November ($2,171\;inds/m^3$). D-shape, early umbone and advanced umbone stage larvae composed of 76%, 18% and 6%, respectively, of total bivalve larvae. Nine larval species of bivalve were identified in this study. The mean abundance of Scapharca subcrenata larvae was $14,030\;inds/m^3$, which was 33.5% of total identified larvae. S. broughtonii (16.2%), Crassostrea gigas (12.5%), Mytilus edulis (10.2%) were also major species in order of their abundance. Considering the monthly larval occurrence in Deukryang Bay, main spawning month of bivalves except M. edulis and M. senhausia was estimated as July. Even though the spatial distribution of bivalve larvae in Deukryang Bay was different by the species, the larvae were generally abundant in the inner and west area of the bay, where was shallower and higher water temperature than the entrance and east area of the bay.

• Animal Systematics, Evolution and Diversity
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• v.18 no.1
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• pp.1-12
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• 2002

Actaea semblatae (Guinot, 1976) has been roared in the laboratory, from hatching to the first young crab stage at $25^{\circ}C$. The two zoeal stages are described and illustrated in detail. The first zoea of A. semblatae in the present study slightly differs from that described by Terada (1987) on the respect of the setal presence on the carapace, the antennule, the coxa of the first maxilliped and the first abdominal somite. Within the family Xanthidae, the zoea of A. semblatae can be clearly distingushed from the other known zoeas by having a seta as an antennal exopod or a vestigial exopod with a sets. A provisional key is provided to aid the identification of the xanthid zoeas in Korea.

• The Korean Journal of Zoology
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• v.30 no.3
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• pp.277-291
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• 1987

틸보꼬마풀게 (Hemigrapsus sinensis Rathbun) (바위 게 과, 참게 아과)의 유생을 부추에서부터 첫번째 게퇘까지 수온 20.2$^{\circ}C$에서 24.1$^{\circ}C$, 염분농도 32,9도에서 33.2%o에서 사육하고, 각 유생기의 형태적인 특징을 기술 및 도시하여, 같은 속내에 보고된 다른 7종의 유생들과 kk교하였다. 이 종은 5기의 Zoea와 1기의 Megalopa 유생을 거쳐 첫번째 게탰로 변태하였다. 제 1 Zoea기의 제 1촉각과 미절이 Aikawa의 기준에 의한 공형이며 갑측극은 있고 제 2소악내지의 강량식이 2.2인 점에서는 같은 속의 다른 7종과 일치하나, 제 1악각의 기절 및 내파와 제 2악각의 내지의 강모식에 약간의 차리가있다.

• Animal Systematics, Evolution and Diversity
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• v.20 no.1
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• pp.1-8
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• 2004

The first zoea of R. uritai is described in detail, based on laboratory-hatched material. The first zoea of R. uritai can be distinguished from that of R. conspiciocellus and R. durbanensis by the rostrum downwards, overreaching distal margin of the outer flagellum of the antenna, the endopod of the antenna with short seta as well as long plumose seta distally, and the scale of the antenna six-segmented. The shape of the telson can be a distinguishing character of the first zoea of Rhynchocinetes from that of Cinetorhynchus.

• Animal Systematics, Evolution and Diversity
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• v.10 no.2
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• pp.145-155
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• 1994

The zoeal development of the pilumnid crab, Pilumnus minutus De Haan, 1835 consisted of 4 zoeal stages. The duration of the zoeal stages was at least 15 days at $25^{\circ}C$. The morphology of the zoeal stage is described in detail, and comparisons are made with the known larvae of other species of the family pilumnidae. The Pilumnus minutus zoea strongly resembles zoeae of other species of the genus Pilumnus in the mouthpart setation and the carapace spines, but shows some differences in the abodominal lateral knobs. the Pilumnus minutus zoea has some affinities with the Parapilumnus trispinosus zoea by having the abodominal lateral knobs on somites 2, 3, 4 and 5.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.369-375
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• 2004

This experiment was studied to obtain basic environmental effects and biological information on the early growth of larval mitten crab (Eriocheir sinensis). Mitten crabs were maintained for each larval stage with solutions containing 0.1, 0.2, and 0.3 ppm of cadmium (Cd) and mercury (Hg). The relationship between survival rate of mitten crabs and metal content in the growth chamber showed a positive correlations. However, it showed a significant difference in the 96 $hr- LC^{50}$ values of Cd and Hg for the E. sinensis larvae from the first zoea larva to juvenile. Hg was more toxic to E. sinensis larval than Cd. When Cd and Hg are released into the water, they enter E. sinensis larval and are biological magnified. These results of survival rate and bioaccumulation are very important when considering the survival of the mitten crab.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.11-19
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• 2016

Field observation for oceanic conditions and paralarvae of the common squid, Todarodes pacificus in Korean waters were sampled with the Bongo net (diameter: 60 cm, mesh size: $333{\mu}m$) by using oblique tow method with the oceanographic research vessel (Tamgu 12 and Tamgu 20) around Korean waters (middle of the Yellow Sea, northern part of the East China Sea, East Sea) in 2013 and 2014 was carried out. The observation in the Yellow Sea and the northern part of the East China Sea was done in August, 2013 and in the East Sea it was repeated at seven times from June, 2013 to September, 2014. The paralarvae in August of 2013 was not found in the Yellow Sea and one paralarvae was found in the northern part of the East China Sea. In the East Sea, 39 paralarvae during whole observation period were found, mantle length of paralarvae was from 1.7 to 13.5 mm. Surface water temperature in the Yellow Sea was $30^{\circ}C$, and cold water mass lower than $10^{\circ}C$ was occupied in the deep layer than 30 m. In the northern part of the East China Sea, surface water temperature was $31^{\circ}C$, and higher water temperature above $20^{\circ}C$ was found in deeper than 50 m. In the East Sea, optimum temperature for survival, $15-24^{\circ}C$, was existed shallower than 75 m.